• Code: C6990
• Description: Fuser power source destination error The information mismatches between the engine backup and the IH PWB.
• Remedy: 1 Executing U169 The voltage setting at U169 mismatches the voltage of the IH PWB. Set the destination same as the voltage of the IH PWB at U169. Maintenanc e Mode List 2 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 3 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7001
• Description: Container motor error 1. After the container motor is started, ready signal does not turn on even 2s passed. 2. After the container motor is stabilized, ready signal is kept off 2s continuously
• Remedy: 1 Replacing the toner container The toner container locks up and is not rotated. Replace the toner container. Replacing the Toner Container (Operation Guide - Section 10) 2 Checking the toner container drive parts The toner container drive parts are not operated properly, or the excessive load is applied to it. Execute U030 [Container Mix] to check the container motor operation. If the container motor does not operate properly, clean the drive gears and the couplings in the container drive unit and apply the grease (EM- 50LP, Part no.: 7BG010009H) to them. Maintenanc e Mode List 3 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Container motor - Feed image PWB Section 8 "PWBs" 4 Checking the toner container motor The toner container motor is faulty. Reattach the container motor and reconnect the connector. If not repaired, replace it. Detaching and reattaching the Container Motor 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 6 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7101
• Description: T/C sensor K error The output value of T/C sensor is not settled within +100 (Toner is not detected) or -1000 (sensor connector is coming off) against the initial toner setting value which is stored in the EEPROM of the developer unit. And this condition was detected 3 times continuously.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit K so that the connector firmly connects. Detaching and reattaching the Developer Unit 2 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Drum/developer relay PWB - Feed image PWB . Feed image PWB - Engine PWB Section 8 "PWBs" 3 Replacing the drive gear The drive gear for the developer unit K is broken. (The developer screw does not rotate.) Replace the developer unit K drive gear. 4 Developer unit replacement Developer unit K (T/C sensor K) is faulty. Replace developer unit K. Detaching and reattaching the Developer Unit 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Detaching and reattaching the Drum/ Developer relay PWB (Section 4 "Detaching and reattaching the waste toner box unit") 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7102
• Description: T/C sensor C error The output value of T/C sensor is not settled within +100 (Toner is not detected) or -1000 (sensor connector is coming off) against the initial toner setting value which is stored in the EEPROM of the developer unit. And this condition was detected 3 times continuously.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit C so that the connector firmly connects. Detaching and reattaching the Developer Unit 2 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Drum/developer relay PWB - Feed image PWB . Feed image PWB - Engine PWB Section 8 "PWBs" 3 Replacing the drive gear The drive gear for the developer unit C is broken. (The developer screw does not rotate.) Replace the drive gear for developer unit C. 4 Developer unit replacement Developer unit C (T/C sensor C) is faulty. Replace the developer unit C. Detaching and reattaching the Developer Unit 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Detaching and reattaching the Drum/ Developer relay PWB (Section 4 "Detaching and reattaching the waste toner box unit") 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7103
• Description: T/C sensor M error The output value of T/C sensor is not settled within +100 (Toner is not detected) or -1000 (sensor connector is coming off) against the initial toner setting value which is stored in the EEPROM of the developer unit. And this condition was detected 3 times continuously.
• Remedy: Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit M so that the connector firmly connects. Detaching and reattaching the Developer Unit 2 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Drum/developer relay PWB - Feed image PWB . Feed image PWB - Engine PWB Section 8 "PWBs" 3 Replacing the drive gear The drive gear for the developer unit M is broken. (The developer screw does not rotate.) Replace the drive gear for developer unit M. 4 Developer unit replacement Developer unit M (T/C sensor M) is faulty. Replace the developer unit M. Detaching and reattaching the Developer Unit 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Detaching and reattaching the Drum/ Developer relay PWB (Section 4 "Detaching and reattaching the waste toner box unit") 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7104
• Description: T/C sensor Y error The output value of T/C sensor is not settled within +100 (Toner is not detected) or -1000 (sensor connector is coming off) against the initial toner setting value which is stored in the EEPROM of the developer unit. And this condition was detected 3 times continuously.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit Y so that the connector firmly connects. Detaching and reattaching the Developer Unit 2 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Drum/developer relay PWB - Feed image PWB . Feed image PWB - Engine PWB Section 8 "PWBs" 3 Replacing the drive gear The drive gear for the developer unit Y is broken. (The developer screw does not rotate.) Replace the drive gear for developer unit Y. 4 Developer unit replacement Developer unit Y (T/C sensor Y) is faulty. Replace the developer unit Y. Detaching and reattaching the Developer Unit 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Detaching and reattaching the Drum/ Developer relay PWB (Section 4 "Detaching and reattaching the waste toner box unit") 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7200
• Description: Inner thermistor broken (developer) Input sampling value of the T/C sensor K (machine inside thermistor) is over the standard value.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit K so that the connector firmly connects. Detaching and reattaching the Developer Unit 2 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Drum/developer relay PWB - Feed image PWB Section 8 "PWBs" 3 Developer unit replacement Developer unit K (T/C sensor K) is faulty. Replace developer unit K. Detaching and reattaching the Developer Unit 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 5 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Detaching and reattaching the Drum/ Developer relay PWB (Section 4 "Detaching and reattaching the waste toner box unit") 6 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7210
• Description: Inner thermistor short-circuited (developer) Input sampling value of the T/C sensor K (machine inside thermistor) is below the standard value.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit K so that the connector firmly connects. Detaching and reattaching the Developer Unit 2 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Drum/developer relay PWB - Feed image PWB Section 8 "PWBs" 3 Developer unit replacement Developer unit K (T/C sensor K) is faulty. Replace developer unit K. Detaching and reattaching the Developer Unit 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 5 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Detaching and reattaching the Drum/ Developer relay PWB (Section 4 "Detaching and reattaching the waste toner box unit") 6 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.